Generally, magnetic survey is one of the most commonly used methods for determining geological structure or detecting mineral resources in mineral resource surveys.
In particular, aeromagnetic survey is the most basically used in survey of resources, and is applied not only to inspection of geological structure over wide areas, but also to direct survey of an iron mine, uranium mine or diamond mine.
Aeromagnetic survey is suited to survey of jungles, lakes, landmines or the like, where land survey is difficult.
A conventional aeromagnetic survey generally employs a helicopter or a fixed-wing airship, and techniques using an unmanned airship for magnetic survey have been developed in recent years.
One example of such techniques is disclosed in PCT/CA05/01557, entitled “UNMANNED AIRBORNE VEHICLE FOR GEOPHYSICAL SURVEY”.
In this publication, an airplane is used to perform unmanned operation based on an unmanned aircraft and a magnetic force of geological stratum is measured using a magnetometer.
However, in the publication, a fuselage of the airplane and various components constituting the airplane are made of metallic materials, causing an increase in the total weight of the unmanned airplane.
As a result, there are problems in that the total operation time of the unmanned airplane is shortened, the airplane has a low payload capacity, magnetism can be generated in the airplane depending on ferruginous contents, and production costs become enormous in use of special lightweight and nonmagnetic alloys.